Modelling concurrent structural mechanical mechanisms in microstructure solidification

Experimental observations point to structural mechanics as a factor that can significantly alter the development of a cast metal alloy’s microstructure. Forces such as gravity or drag due to solute flow can induce dendrites to deform and/or change orientation. Such changes in microstructural development can lead to defects including stray grains and slivers that degrade macroscopic material properties. However, the interaction of microstructure evolution with structural mechanics is often neglected as a factor in numerical models, potentially rendering them incapable of capturing key defect formation mechanisms. A numerical method coupling a Finite Volume Structural Mechanics solver to a Cellular Automata microstructure solidification solver has been developed, where the growth behaviour of solidifying dendrites is altered by changes to the crystallographic orientation obtained from the calculated displacements. Scenarios where small deformations lead to large orientation changes to accumulate were examined, finding the behaviour to be analogous to that observed in experiments.